title: Cis-regulatory underpinnings of human GLI3 expression in embryonic craniofacial structures and internal organs.
abstract: The zinc finger transcription factor Gli3 is an important mediator of Sonic hedgehog (Shh) signaling. During early embryonic development Gli3 participates in patterning and growth of the central nervous system, face, skeleton, limb, tooth and gut. Precise regulation of the temporal and spatial expression of Gli3 is crucial for the proper specification of these structures in mammals and other vertebrates. Previously we reported a set of human intronic cis-regulators controlling almost the entire known repertoire of endogenous Gli3 expression in mouse neural tube and limbs. However, the genetic underpinning of GLI3 expression in other embryonic domains such as craniofacial structures and internal organs remain elusive. Here we demonstrate in a transgenic mice assay the potential of a subset of human/fish conserved non-coding sequences (CNEs) residing within GLI3 intronic intervals to induce reporter gene expression at known regions of endogenous Gli3 transcription in embryonic domains other than central nervous system (CNS) and limbs. Highly specific reporter expression was observed in craniofacial structures, eye, gut, and genitourinary system. Moreover, the comparison of expression patterns directed by these intronic cis-acting regulatory elements in mouse and zebrafish embryos suggests that in accordance with sequence conservation, the target site specificity of a subset of these elements remains preserved among these two lineages. Taken together with our recent investigations, it is proposed here that during vertebrate evolution the Gli3 expression control acquired multiple, independently acting, intronic enhancers for spatiotemporal patterning of CNS, limbs, craniofacial structures and internal organs.
authors.affiliation: Faculty of Biological Sciences, National Center for Bioinformatics, Program of Comparative and Evolutionary Genomics, Quaid-i-Azam University, Islamabad, 45320, Pakistan.
authors.forename: Amir A
authors.initials: AA
authors.lastname: Abbasi
authors.forename: Rashid
authors.initials: R
authors.lastname: Minhas
authors.forename: Ansgar
authors.initials: A
authors.lastname: Schmidt
authors.forename: Sabine
authors.initials: S
authors.lastname: Koch
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Grzeschik
mesh_terms: D000818:Animals; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D006801:Humans; D007438:Introns / Q000502:physiology*; D051741:Kruppel-Like Transcription Factors / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D008822:Mice, Transgenic; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics; D054259:Neural Tube / Q000196:embryology; D009928:Organ Specificity / Q000502:physiology; D038081:Organogenesis / Q000502:physiology*; D012886:Skull / Q000196:embryology*; D014158:Transcription, Genetic / Q000502:physiology*; D000074290:Zinc Finger Protein Gli3
chemical_list: C065683:GLI3 protein, human; C465571:Gli3 protein, mouse; D051741:Kruppel-Like Transcription Factors; D009419:Nerve Tissue Proteins; D000074290:Zinc Finger Protein Gli3
keywords: GLI3 expression; conserved non-coding elements; enhancer; transgenic mice; zebrafish